Ovarian cancer is a highly lethal gynecologic cancer with an estimated 21,860 new cases and approximately 13,850 deaths in the USA per year. In a large majority of the patients, cancer reoccurs after initial treatment and manifest resistance to conventional and novel chemotherapeutic agents, thereby representing a formidable clinical challenge which could be mitigated by the production of novel, targeted therapies. Recently, the Donahoe laboratory at the Massachusetts General Hospital (MGH) showed that recombinant human Mllerian Inhibiting Substance (rhMIS) specifically targets ovarian cancer cell populations that respond poorly to the currently used chemotherapeutic agents indicating that MIS could be used as an innovative, targeted medicine to address recurrent multidrug resistant ovarian cancer. In vivo when MIS was tested in mice as a single agent it was found to inhibit tumor growth in experiments lasting 80 to 100 days. Additionally since MIS receptor expression is limited in endogenous tissue; systemic toxicity of rhMIS is expected to be low. A significant unmet need hindering the progress of an rhMIS treatment for ovarian cancer is the development of scaled production of the protein with reasonable economics. This R43 proposal describes the parallel molecular biology processing methods to scale production of a new construct that provides for enhanced cleavage, purity, and potency for use as a standard preparation to study in preclinical trials and for subsequent use in phase I clinical trials against human ovarian cancer, the latter of which will be the subject of another grant for which the MIS produced by the present proposal will lay the foundation for the eventual material used. The team from Nemucore Medical Innovations (NMI), Blue Sky BioServices, and MGH propose as the subject of this R43 application to develop and characterize the methods and processes required to produce rhMIS in single use disposable biomanufacturing equipment. NMI is establishing a modular biomanufacturing facility compliant with the FDA's pharmaceutical quality system guidance to enable such novel biotherapeutics as rhMIS for clinical investigation.